Synthesis of 4-(Acylacetyl)-1-phenyl-2-pyrazolin-5-ones from 3-Acyl-2H-pyran-2,4(3H)-diones. Their Synthetic Applications to Functionalized 4-Oxopyranopyrazole Derivatives.

Article abstract of DOI:10.1021/jo00170a041

The phenylhydrazones of 3-acyl-2H-pyran-2,4(3H)-diones (2), in refluxing acetic acid, underwent rearrangement to 4-(acylacetyl)-1-phenyl-2-pyrazolin-5-ones (6), from which some functionalized 4-oxopyrano<2,3-c>pyrazole derivatives were synthesized.This fi